Mixtures of surfactants used as wetting agents and/or emulsifiers in agrochemical preparations

ABSTRACT

The present invention relates to surfactant mixtures with improved wetting and/or emulsifying properties for use in agrochemical preparations, comprising: A) at least an alkylpolyglucoside, B) at least an anionic derivative of an alkylpolyglucoside, and C) at least an anionic derivative of a fatty alcohol.

FIELD OF THE INVENTION

The present invention relates to surfactant mixtures used as wettingagents and/or as emulsifiers in agrochemical preparations, particularlyin pesticide compositions.

STATE OF THE ART

The pesticide active ingredients—according to the characteristics of theactives and of their intended applications—can be formulated as dusts,wettable powders, dispersible granules, suspension concentrates,emulsifiable concentrates, emulsions and concentrated solutions, andtheir application as formulated products on soil, seeds or plant foliageis generally carried out with aqueous spray in form of solution,suspension or emulsion.

Surfactants are commonly used in order to disperse and suspend the solidsubstances, or to emulsify the oily liquids in water, formingsuspensions or stable emulsions. The surfactants help the formation ofaqueous dispersions of compounds insoluble in water. Moreover thesurfactants reduce the surface tension between aqueous spray and thematerial (soil, seeds, foliage) to be treated, thus favouring thespreading of droplets on the treated surface and the penetration of theactive ingredient into the materials.

Among surfactants, which can be used for the aforementioned purposes,the aliphatic polyglucosides have been known for a long time. Thesematerials offer several advantages due to their low toxicity and goodbiodegradability, and even have certain fungicide, insecticide, andacaricide activities. Due to these features, the organic polyglucosidesprovide, in agrochemical formulations and applications, a wider spectrumof functions, since other equivalent traditional surfactants arenormally used only as wetting agents and/or emulsifiers.

For instance, U.S. Pat. No. 4,888,325 describes pesticide compositionsthat contain alkylglucosides, alone or in combination with othersurfactants. However, such compositions show weak wetting performanceand cannot sufficiently reduce the interfacial tension between theaqueous spray and the material on which said spray is applied.

U.S. Pat. No. 5,385,750 describes the use of aliphatic polyglucosides asco-adjuvant in pesticide formulations in combination with fatty alcohol.According to U.S. Pat. No. 5,385,750 the addition of fatty alcohol tothe alkylpolyglucosides increases its wetting performance, favouring thepenetration of the pesticide active ingredient into biologicalmaterials, even when the treated surface layers are waxy or oily as inthe case of foliage.

On the other hand, the presence of a fatty alcohol creates considerabledrawbacks: it gives bad odours and causes a noticeable lowering of theemulsifying ability of the alkylpolyglucosides.

Therefore, it is still an unresolved problem to obtain compositionsbased on aliphatic polyglucosides having better wetting properties,maintaining good emulsifying characteristics, without the drawbacksexperienced with the known products as described above.

SUMMARY OF THE INVENTION

Now the Applicant has found that the use, as wetting agent and/oremulsifier, of a mixture comprising at least an alkylpolyglucoside, atleast an anionic derivative of an alkylpolyglucoside and at least ananionic derivative of a fatty alcohol, in suitable weight ratio, hasunexpected advantages in the application of agrochemical preparations onsoil, seeds and plants, particularly when aqueous sprays of pesticideformulations are used.

These surfactant mixtures show the required efficacy in the formation ofstable systems with water and organic substances and, moreover, theyincrease the penetration of the pesticide active ingredient intobiological materials, due to a superior wetting power as compared tothat of aliphatic polyglucosides used alone.

Additionally, the substances contained in the present mixtures arequickly biodegradable and satisfy the request of low toxicity for themammals and low irritating effect in contact with the epidermis, thusbeing suitable for the use in pesticide preparations to be applied onedible plants; the mixtures of the present invention are indeed free ofharmful or toxic by-products, like amines, ethylene oxide, 1,4-dioxane,alkyl phenols, etc.

Therefore the subject of the present invention is a surfactant mixturesuitable for the use as wetting agent and/or emulsifier in pesticideagrochemical compositions, characterised by comprising:

A) at least an alkylpolyglucoside,

B) at least an anionic derivative of an alkylpolyglucoside, and

C) at least an anionic derivative of a fatty alcohol.

Further subjects of the present invention are the aqueous compositionsof pesticides comprising such surfactant mixture, and their use inagriculture for the treatment of seeds, plants and soil.

The characteristics and the advantages of the surfactant mixturesaccording to the present invention will be illustrated in detail in thefollowing description.

DETAILED DESCRIPTION OF THE INVENTION

The present surfactant mixture comprises at least an alkylpolyglucoside,at least an anionic derivative of an alkylpolyglucoside and at least ananionic derivative of a fatty alcohol.

Examples of alkylpolyglucosides, according to the aim of the presentinvention are the aliphatic alkylpolyglucosides represented by thefollowing formula (I)

R—O—(G)_(x)  (I)

where:

R is a saturated or unsaturated aliphatic group having from 6 to 20carbon atoms, linear or branched;

O is an oxygen atom;

G is a residue of a reducing saccharide connected to R—O by means of anethereal O-glycosidical bond;

x is a number from 1 to 10, representing the average degree ofoligomerization of G.

Preferably R is an alkyl group having from 8 to 16 atoms of carbon, G isa residue of a reducing saccharide and x is a number between 1 and 2.

The preferred alkylpolyglucosides, according to the invention, arecompounds of formula (I) in which G is a residue of glucose.

The compounds of formula (I) are known, as well as their methods ofpreparation, and are for instance described in U.S. Pat. Nos. 3,219,656,3,547,828 and 3,839,318.

Preferred compounds of formula (I) reported above are commerciallyavailable products and are endowed with an high biodegradability.

Examples of anionic derivatives of alkylpolyglucosides according to theaim of the present invention are compounds represented by the followingformula (II)

[R′—O—(G)_(x)]_(n)—(D)_(y)  (II)

where:

R′ is a aliphatic group, saturated or unsaturated, linear or branched,having from 6 to 20 atoms of carbon, preferably from 8 to 16 atoms ofcarbon;

G is a residue of a reducing saccharide, preferably of glucose,connected to R′—O by means of an ethereal O-glycosidical bond;

O is an oxygen atom;

D is an acyl residue connected to an oxygen atom of the residue G, andderived from a bicarboxylic acid or a polycarboxylic acid having analiphatic chain from 2 to 8 carbon atoms, linear or branched, saturatedor unsaturated, not substituted or substituted with one or more hydroxylgroups, and in which at least one carboxylic group is salified or inacid form;

n is a number between 1 and m−1, where m is the number of carboxylicgroups in the acid that originates D;

x has the same meaning as described above for the compounds of formula(I);

y is a number from 1 to 10 representing the degree of averageesterification of (G)_(x).

Preferred anionic derivatives of alkylpolyglucosides according to thepresent invention, are compounds of formula (II), in which R′ is analkyl group having from 8 to 16 atoms of carbon and D is the acylresidue of a carboxylic acid selected from the group consisting ofcitric acid, tartaric acid, maleic acid and malic acid.

The above mentioned anionic derivatives of alkylpolyglucosides offormula (II) are known and they can be prepared as described, forexample, in EP 258 814, or in EP 510 564.

Examples of anionic derivatives of fatty alcohols according to thepresent invention are represented by the following formula (III)

R″—O—D′  (III)

and they can be prepared by esterification of a carboxylic acid with afatty alcohol of formula R″—OH, where:

R″ is an aliphatic group, saturated or unsaturated, linear or branched,having from 6 to 20 atoms of carbon, preferably from 8 to 16 atoms ofcarbon;

O is an oxygen atom;

D′ is an acyl residue of a bicarboxylic acid or of a polycarboxylic acidhaving an aliphatic chain with from 2 to 8 atoms of carbon, saturated orunsaturated, linear or branched, not substituted or substituted with oneor more hydroxyl groups, and in which at least one carboxyl group issalified or in its acid form.

Preferred anionic derivatives of fatty alcohols according to the presentinvention are compounds of formula (III) in which D′ is an acyl residueof a carboxylic acid selected from the group consisting of citric acid,tartaric acid, malic acid and maleic acid.

An example of preparation of the anionic derivatives of fatty alcoholsof formula (III) has been reported in the article “Citric EsterSurfactants”—P. J. Borchert et al.—Proceeding of the World SurfactantsCongress—Munich 1984, vol. 2, pag. 147. Particularly relevant for therealisation of the present invention are the anionic derivatives ofalkylpolyglucosides (II) and the anionic derivatives of fatty alcohol(III) in which D and D′ are acyl residues of citric acid with at leastone carboxylic group salified, preferably in the form of sodium salt.

In the surfactant mixture according to the present invention, the Rgroup in the compound of formula (I), the R′ group in the compound offormula (II) and the R″ group of the fatty alcohol of formula (III) canbe equal or different from one another; surfactant mixtures in whichR=R′=R″ have wetting and emulsifying power particularly high.

Similarly, in the surfactant mixture according to the present invention,the D group in the compound of formula (II) and the D′ group in thecompound of formula (III) can be equal or different from one another;the surfactant mixtures in which D=D′ have wetting and emulsifying powerparticularly high.

According to the present invention, particularly preferred aresurfactant mixtures in which R=R′=R″ and simultaneously D=D′.

In the present surfactant mixture composition the quantity of eachcomponent ranges between 1 and 98% by weight with respect to the totalweight of the mixture.

According to a preferred embodiment of the present invention, thesurfactant mixture composition, expressed as percentage by weight ofeach component with respect to the total weight of the mixture, is thefollowing:

A) alkylpolyglucoside of formula (I) 20-60% B) anionic derivative ofalkylpolyglucoside of formula (II) 20-50% C) anionic derivative of fattyalcohol of formula (III) 10-30%

The present surfactant mixture may comprise from 0 to 97% by weight ofwater with respect to the total weight of the mixture.

The surfactant mixture of the present invention can be used to formulateactive ingredients in form of wettable powders, dispersible granules,concentrated suspensions, concentrated emulsions, microemulsions,macroemulsions, microencapsulated products, solutions, etc., thusobtaining a composition to be applied as such, or in a diluted form withwater or with other appropriate solvent at the required dilution ratio;said composition can be prepared at the required dilution right beforeuse too.

In a particular embodiment of the invention, it is generally preferredto add the present surfactant mixture to the formulated pesticide, andthen to dilute with water to the desired concentration in order toobtain an aqueous sprayable composition of the formulated pesticide.

According to a particular embodiment of the present invention, theagrochemical compositions comprising the surfactant mixture, comprise atleast an active ingredient, for example with pesticide action, and acarrier, for instance water; preferably, in such compositions thequantity of surfactant mixture is from 1 to 90% in weight, with respectto the total weight of the composition, the quantity of the activeingredient is from 1 and 90% by weight, while the quantity of carriermakes up the balance of the composition.

Said agrochemical compositions can further comprise:

one or more active ingredients with various functions, for instanceinsecticide, acaricide, fungicide, nematocide, disinfectant, herbicide,fertilizer or micronutrient;

other surfactants, besides those of the surfactant mixture subject ofthe invention;

other products, such as antifoam agents, antifreeze agents, dyes,stabilisers and buffers;

usual additives of agrochemical compositions.

Preferably, the present surfactant mixture is used in aqueous sprayformulations of pesticides, comprising for example:

said surfactant mixture in an amount from 0.1 to 20% by weight withrespect to the total weight of the composition, preferably from 1 to 10%by weight;

the concentrated formulation of the pesticide active ingredient, inquantity between 0.1 and 20% by weight;

water,

and, optionally, other concentrated formulations of active ingredients,micronutrients, other surfactants and/or other additives commonly usedin the agrochemical compositions, in such an amount which makes up thebalance of the composition.

Said agrochemical compositions can comprise pesticide active compounds,such as Acephate, Acetochlor, Alachlor, Alphacypermethrin, Amitraz,Atrazine, Benomyl, Bentazon, Bromacil, Captan, Carbaryl, Carbendazim,Carbofuran, Carboxin, Chloridazon, Chlorpyriphos, Chlorthalonil,Chlortoluron, Copper oxychloride, Copper oxyquinolate, Cypermethrin,Cyromazine, Dalapon, Deltamethrin, Diazinone, Dicamba, Dichlorprop,Dicofol, Dimethoate, Dinocap, Diuron, Dodine, Endosulfan, Ethofumesate,Ethylparathion, Fenitrothion, Fenthion, Fentin Hydroxide, Fluometuron,Folpet, Fosetyl-AI, Glufosinate, Glyphosate, Lindane, Linuron,Malathion, Mancozeb, MCPA, MCPB, Metalaxyl, Methamidophos, Methomyl,Methylparathion, Metobromuron, Metolachlor, Naled, Oxadiazon, Paraquat,Pendimethalin, Permethrin, Phenmedipham, Pyperonilbutoxide, Pirethrum,Propachlor, Propanil, Propiconazol, Propisochlor, Propoxur,Quizalofop-P-tefuryl, Sethoxydim, Simazine, Sulphur, Temephos,Tetraconazol, Tetramethrin, Thiophanate methyl, Thiram, Triadimefon,Triadimenol, Trifluralin, Vinclozolin, Zineb, Ziram, and their mixtures.

The surfactant mixture of the present invention is particularly suitedfor agrochemical formulations comprising N-(phosphonomethyl)glycine(Glyphosate) or its salts, preferably the isopropylammonium salt ofN-(phosphonomethyl)glycine (Glyphosate isopropylammonium), which is fromhere on referred to as Glyphosate IPA.

The Applicant has found that the use of said surfactant mixture indilutable with water or aqueous compositions of pesticides has anemulsifying effect and wetting performance, which can help the formationof an homogeneous dispersion of the pesticide in water, thusaccelerating its penetration in the treated biological materials (soil,seeds or plant foliage), in an unexpectedly higher degree as compared tothe known prior art where only alkylpolyglucosides are used.

The aforementioned characteristics of said surfactant mixtures aredetermined by measurement of the superficial tension and determinationsof the wetting power, as illustrated in the following Examples.

The following examples will serve to further illustrate the inventionand are intended to be illustrative and not limiting of the presentinvention. The following experimental examples were carried out with thesurfactant mixtures of the present invention and using the followingprior art products:

an aqueous solution (70% water) of an alkylpolyglucoside with a degreeof glucose oligomerization of 1.2, free alcohol content of less than 1%,and with the following composition of the lipophilic chain:

C10=26.0%

C12=50.0%

C14=23.5%

C16=0.5%.

This aqueous solution is referred to from here on as ALKPG/30.

ethoxylated tallow amine, with an average ethoxylation degree of 15 EOmole/mole (EMULSON® GPE 3 SS, CESALPINIA SpA).

EXAMPLE 1

Preparation of the Surfactant Mixture of the Invention (Mixture 1)

a) Preparation of the Alkylpolyglucoside

In a reaction vessel equipped with heating, cooling, strirrer,thermometer, a system of introduction of the reagents, such reactionvessel being connected both to a cooler provided of collector of waterof reaction, and to a vacuum pump, the following components are added,under stirring: 930 g (5 mol) of a mixture of decyl alcohol, dodecylalcohol, tetradecyl alcohol and hexadecyl alcohol with ratio26:50:23.5:0.5, and 1.4 g of p-toluenesulphonic acid monohydrate. Thetemperature is set at 120° C. while the vacuum pump applies a pressureof 50-60 mm Hg. At temperature of 120° C., 180 g (1 mol) of anhydrousglucose are added, in constant portions every 10 minutes, in a period ofabout 120 minutes. At the end of the last addition the temperature of120° C. is maintained for further 30 minutes, then the temperature isdecreased to 50-60° C. and the neutralisation is carried out with 1 g ofa 30% solution of sodium hydroxide. The obtained product is analkyl(C10-C12-C14-C16)polyglucoside containing about 75% of free fattyalcohol. By means of distillation on thin layer at 150° C. and at apressure of 2 mmHg, the main part of unreacted fatty alcohol isdistilled off, thus yielding an alkyl(C10-C12-C14-C16)polyglucosidecontaining about 27% of free fatty alcohol. The degree of glucoseoligomerization is about 1.2.

b) Preparation of the Ester and Its Salification

In a reactor analogous to that used in phase a), 100 g of the productprepared in the phase a) are introduced. The temperature is adjusted to130° C. under stirring; at this temperature 63.7 g of citric acid areadded over a period of about 1 hour. The reaction mixture is maintainedat 130° C. until the acidity number reaches 236 (±5) mg/g of KOH. Thenthe reaction mixture is cooled down to 110-115° C. and a dilution ismade with 327.6 g of water. The temperature is furthermore decreased to30° C. and 88.7 g of a 30% aqueous solution of caustic soda, are added,over a period of about 1 hour. In this way, about 570 g of an 30%aqueous solution is obtained, where the dry fraction consists of about66% of alkylpolyglucoside citric ester sodium salt and of about 33% offatty alcohol citric ester sodium salt.

c) Final Mixing

To 120 g of the mixture of esters obtained in the b phase) the followingquantities of alkylpolyglucoside ALKPG/30 are added under stirring inorder to obtain homogeneous products:

80 g of ALKPG/30 (Mixture 1.1)

146.7 g of ALKPG/30 (Mixture 1.2)

280 g of ALKPG/30 (Mixture 1.3)

680 g of ALKPG/30 (Mixture 1.4)

EXAMPLE 2

Preparation of the Surfactants Mixture of the Invention (Mixture 2)

a) Preparation of the Alkylpolyglucoside.

In a reaction vessel equipped with heating, cooling, strirrer,thermometer, a system of introduction of the reagents, such reactionvessel being connected both to a cooler provided of collector of waterof reaction, and to a vacuum pump, the following components are added,under stirring: 930 g (5 mol) of a mixture of decyl alcohol, dodecylalcohol, tetradecyl alcohol and hexadecyl alcohol with ratio26:50:23.5:0.5, and 1.4 g of p-toluenesulphonic acid monohydrate. Thetemperature is set at 120° C. while the vacuum pump applies a pressureof 50-60 mm Hg. At temperature of 120° C., 180 g (1 mol) of anhydrousglucose are added in portions in about 120 minutes. At the end of thelast addition the temperature of 120° C. is maintained for another 30minutes, then the temperature is decreased to 50-60° C. and theneutralisation is carried out with 1 g of a 30% solution of sodiumhydroxide. The obtained product is analkyl(C10-C12-C14-C16)polyglucoside containing about 75% of free fattyalcohol. By means of distillation on thin layer at 150° C. and at apressure of 2 mmHg, the main part of unreacted fatty alcohol isdistilled off, thus yielding an alkyl(C10-C12-C14-C16)polyglucosidecontaining about 28% of free fatty alcohol. The degree of glucoseoligomerization is about 1.2.

b) Preparation of the Ester and Its Salification

In a reactor analogous to that used in phase a), 100 g of the productprepared in the phase a) are introduced. The temperature is adjusted to130° C. under stirring; at this temperature 50.2 g of tartaric acid areadded over a period of about 1 hour. The reaction mixture is maintainedat 130° C. until the acidity number reaches 130±3 mg/g of KOH. Then thereaction mixture is cooled down to 110-115° C. and a dilution is madewith 316.4 g of water. The temperature is furthermore decreased to 30°C. and 44.7 g of a 30% aqueous solution of caustic soda, are added, overa period of about 1 hour. In this way, about 570 g of an 30% aqueoussolution is obtained, where the dry fraction consists of about 66% ofalkylpolyglucoside tartaric acid ester sodium salt and about 33% offatty alcohol tartaric acid ester sodium salt.

c) Final Mixing

To 80 g of the mixture of esters obtained in the b phase) the followingquantities of alkylpolyglucoside ALKPG/30 are added under stirring inorder to obtain homogeneous products:

120 g of ALKPG/30 (Mixture 2.1)

186.7 g of ALKPG/30 (Mixture 2.2)

320 g of ALKPG/30 (Mixture 2.3)

720 g of ALKPG/30 (Mixture 2.4)

EXAMPLE 3

Preparation of Pesticide Compositions Based on Glyphosate IPA

The surfactant mixtures prepared as described in the Examples 1 and 2,and the products ALKPG/30 and EMULSON GPE 3 SS have been used for thepreparation of pesticide compositions comprising Glyphosate IPA.

These compositions have been prepared by adding the aqueous surfactantmixture and the solution of the active ingredient in the desiredquantities into water reported in Table 1. As active ingredient acommercially available aqueous solution is used, containing 46.2 %Glyphosate IPA. In all these compositions the total amount ofsurfactants is 1% by weight.

The prepared compositions are given in the following Table 1.

TABLE 1 Quantity Composition Components (% by wt.)  1 (Comparison)Glyphosate IPA 1 Water 99  2 (Comparison) Glyphosate IPA 1 ALKPG/30 1Water 98  3 Glyphosate IPA 1 Mixture 1.4 1 Water 98  4 Glyphosate IPA 1Mixture 1.3 1 Water 98  5 Glyphosate IPA 1 Mixture 1.2 1 Water 98  6Glyphosate IPA 1 Mixture 1.1 1 Water 98  7 Glyphosate IPA 1 Mixture 2.41 Water 98  8 Glyphosate IPA 1 Mixture 2.3 1 Water 98  9 Glyphosate IPA1 Mixture 2.2 1 Water 98 10 Glyphosate IPA 1 Mixture 2.1 1 Water 98 11(Comparison) Glyphosate IPA 1 EMULSON ® GPE 3 SS 1 Water 98

EXAMPLE 4

Measurement of the Superficial Tension

On the compositions 1-11 prepared as described in the above Example 3,the measurement of the superficial tension was carried out at atemperature of 20° C., according to the internal method UT 703, whichcorresponds to ASTM D1530 and D971.

The so-determined data of superficial tension in dyne/cm are reported inthe following Table 2.

TABLE 2 Composition Superficial tension (dyne/cm)  1 (Comparison) 63.4 2 (Comparison) 33.4  3 32.8  4 33.1  5 32.8  6 32.0  7 32.9  8 32.5  932.5 10 32.4 11 (Comparison) 46.7

From the analysis of the data given in Table 2 it is clear that thesurfactant mixtures of the invention decrease significantly thesuperficial tension of the compositions compared to those compositionswhich contain only surfactants known by the prior art.

The decrease of superficial tension results in a unexpectedly bettereffectiveness of said surfactant mixtures in dispersing homogeneouslythe pesticide active ingredients in the aqueous compositions, and/or inproviding a uniform distribution of the sprayable compositions on thematerial to be treated.

EXAMPLE 5

Measurement of the Wetting Power

The wetting power of compositions 1, 2, 6, 10 and 11 prepared asdescribed in Example 3, were determined by the following experimentaltests.

The measurements were carried out at the temperature of 20° C. withdetermination of time of sinking of a cotton diskette according to theinternal method NT/016, that refers to DIN 53901, and using theaforementioned compositions in diluted form with water in such a waythat concentration of surfactant is 0.2% by weight.

The obtained data of the time of sinking, expressed in seconds, aregiven in the following Table 3.

TABLE 3 Quantity of surfactant Time of sinking Composition (% by wt.)(seconds)  1 (Comparison) — >1800  2 (Comparison) 0.2 392  6 0.2 44 100.2 40 11 (Comparison) 0.2 >1800

The experimental data reported in Table 3 show clearly that the time ofsinking is notably reduced when the surfactants mixtures of theinvention are used, as a lower sinking time corresponds to an increasedwetting power of the compositions; therefore the data above reportedgive a measure of the velocity with which the pesticide compositions aredistributed on the materials to be treated and of the penetration rateof the active ingredient into the treated surfaces.

What is claimed is:
 1. Surfactant mixture to be used as wetting and/oremulsifying agents in pesticide agrochemical compositions comprising: A)at least an alkylpolyglucoside, B) at least an anionic derivative of analkylpolyglucoside, and C) at least an anionic derivative of a fattyalcohol.
 2. The surfactant mixture according to claim 1, wherein thesaid alkylpolyglucoside is selected from alkylglucosides of formula (I)R—O—(G)_(x)  (I) where: R is an aliphatic group, saturated orunsaturated, linear or branched, having from 6 to 20 atoms of carbon; Ois an oxygen atom; G is a residue of a reducing saccharide connected toR—O by means of an ethereal O-glycosidical bond; x is a number from 1 to10, representing the average degree of oligomerization of G.
 3. Thesurfactant mixture according to claim 2, wherein R is an alkyl grouphaving from 8 to 16 atoms of carbon; G is a residue of glucose; and x isa number between 1 and
 2. 4. The surfactant mixture according to claim1, wherein the said anionic derivative of alkylpolyglucoside B) isselected from compounds of formula(II) [R′—O—(G)_(x)]_(n)—(D)_(y)  (II)where: R′ is an aliphatic group, saturated or unsaturated, linear orbranched, having from 6 to 20 atoms of carbon; O is an oxygen atom; G isa residue of a reducing saccharide, connected to R′—O by means of anethereal O-glycosidical bond; D is an acyl residue connected to anoxygen atom of G, and derived from a bicarboxylic acid or polycarboxylicacid having an aliphatic chain with from 2 to 8 atoms of carbon, linearor branched, saturated or unsaturated, not substituted or substitutedwith one or more hydroxyl groups, and in which at least one carboxylicgroup is salified or in acid form; x is a number between 1 and 10,representing the average degree of oligomerization of G; n is a numberbetween 1 and m−-1, where m is the number of carboxylic groups in theacid that originates D; y is a number between 1 to 10 representing thedegree of average esterification of (G)_(x).
 5. The surfactant mixtureaccording to claim 4, wherein R′ is an alkyl group having from 8 to 16atoms of carbon, G is a residue of glucose, and D is the acyl residue ofa carboxylic acid selected among citric acid, tartaric acid, maleic acidand malic acid.
 6. The surfactant mixture according to claim 5, whereinD is an acyl residue of citric acid with at least a salified carboxylicgroup.
 7. The surfactant mixture according to the claim 1, wherein thesaid anionic derivative of a fatty alcohol C) is selected from thecompounds of formula (III) R″—O—D′  (III) where R″ is an aliphaticgroup, saturated or unsaturated, linear or branched, having from 6 to 20atoms of carbon; O is an oxygen atom; D′ is an acyl residue of abicarboxylic acid or polycarboxylic acid, having an aliphatic chain withfrom 2 to 8 atoms of carbon, saturated or unsaturated, linear orbranched, not substituted or substituted with one or more hydroxylgroups, and in which at least one carboxylic group is salified or inacid form.
 8. The surfactant mixture according to claim 7, wherein R″ isan alkyl group having from 8 to 16 carbon atoms, and D′ is an acylresidue of a carboxylic acid selected from the group consisting ofcitric acid, tartaric acid, malic acid and maleic acid.
 9. Thesurfactant mixture according to claim 8, wherein D′ is an acyl residueof citric acid with at least a salified carboxylic group.
 10. Thesurfactant mixture according to claim 1, wherein: the saidalkylpolyglucoside is selected from alkylpolyglucosides of formula (I)R—O—(G)_(x)  (I); the said anionic derivative of an alkylpolyglucosideis selected from compounds of formula (II)[R′—O—(G)_(x)]_(n)—(D)_(y)  (II); and the said anionic derivative of afatty alcohol is selected from the compounds of formula (III)R″—O—D′  (III) wherein R, R′ and R″ are selected from aliphatic groups,saturated or unsaturated, linear or branched, having from 6 to 20 carbonatoms; D and D′ are selected from acyl residues of a bicarboxylic acidor polycarboxylic acid, having an aliphatic chain with from 2 to 8carbon atoms, saturated or unsaturated, linear or branched, notsubstituted or substituted with one or more hydroxyl groups, and inwhich at least one carboxylic group is salified or in acid form; O is anoxygen atom; G is a residue of a reducing saccharide connected to R—O orR′—O by means of an ethereal O-glycosidical band; x is a number from 1to 10 representing the average degree of oligomerization of G; n is anumber between 1 and m−1, where m is the number of carboxylic groups inthe acid that originates D; y is a number between 1 to 10 representingthe degree of average esterification of (G)_(x).
 11. The surfactantmixture according to claim 10, wherein R=R′=R″.
 12. The surfactantmixture according to claim 10, wherein D=D′.
 13. The surfactant mixtureaccording to claim 10, wherein R=R′=R″ and, simultaneously, D=D′. 14.The surfactant mixture according to claim 1, wherein the amount of eachcomponent A), B) and C) ranges between 1 and 98% by weight with respectto the total weight of the mixture.
 15. The surfactant mixture accordingto claim 14, wherein the amount of alkylpolyglycoside A) is comprisedbetween 20 and 60% by weight with respect to the total weight of themixture, the amount of the anionic derivative of alkylpolyglycoside B)is comprised between 20 and 50% by weight and the amount of the anionicderivative of fatty alcohol C) is comprised between 10 and 30% byweight.
 16. Agrochemical composition with pesticide activity comprisingthe surfactant mixture according to claim 1, at least a pesticide activeprinciple, and a carrier.
 17. The composition according to claim 16,wherein the said active principle is in a form selected from the groupconsisting of wettable powders, dispersible granules, concentratedsuspensions, concentrated emulsions, microemulsions, macroemulsions,microencapsulated products and solutions.
 18. The composition accordingto claim 16, wherein the said active principle is selected from thegroup consisting of Acephate, Acetochlor, Alachlor, Alphacypermethrin,Amitraz, Atrazine, Benomyl, Bentazon, Bromacil, Captan, Carbaryl,Carbendazim, Carbofuran, Carboxin, Chloridazon, Chlorpyriphos,Chlorthalonil, Chlortoluron, Copper oxychloride, Copper oxyquinolate,Cypermethrin, Cyromazine, Dalapon, Deltamethrin, Diazinone, Dicamba,Dichlorprop, Dicofol, Dimethoate, Dinocap, Diuron, Dodine, Endosulfan,Ethofumesate, Ethylparathion, Fenitrothion, Fenthion, Fentin Hydroxide,Fluometuron, Folpet, Fosetyl-Al, Glufosinate, Glyphosate, Lindane,Linuron, Malathion, Mancozeb, MCPA, MCPB, Metalaxyl, Methamidophos,Methomyl, Methylparathion, Metobromuron, Metolachlor, Naled, Oxadiazon,Paraquat, Pendimethalin, Permethrin, Phenmedipham, Pyperonilbutoxide,Pirethrum, Propachlor, Propanil, Propiconazol, Propisochlor, Propoxur,Quizalofop-P-tefuryl, Sethoxydim, Simazine, Sulphur, Temephos,Tetraconazol, Tetramethrin, Thiophanate methyl, Thiram, Triadimefon,Triadimenol, Trifluralin, Vinclozolin, Zineb, Ziram, and the saltsthereof.
 19. The composition according to claim 18, wherein the saidpesticide active principle is the isopropylammonium salt of Glyphosate.20. The composition according to claim 16, further comprising one ormore other active principles having an activity different from thepesticide, fertilisers, micronutrients, surfactants, antifoam agents,antifreeze agents, dyes, stabilisers, buffers, and other additivesusually comprised in agrochemical compositions.
 21. The compositionaccording to claim 16, wherein the amount of the said surfactant mixtureis comprised between 1 and 90% by weight with respect to the totalweight of the composition, the amount of the said active principle iscomprised between 1 and 90% by weight, and the amount of the saidcarrier is as much as to balance the composition.
 22. The compositionaccording to claim 16, wherein the amount of the said surfactant mixtureis comprised between 0.1 and 20% by weight and the amount of theconcentrated formulate comprising the pesticide active principle iscomprised between 0.1 and 20% by weight with respect to the total weightof the composition.
 23. Process for the preparation of an agrochemicalcomposition comprising at least one pesticide active principle, whereinthe improvement comprises adding to the said composition the surfactantmixture according to claim 1 as a wetting and/or emulsifying agent. 24.The process according to claim 23, wherein the said surfactant mixtureis added to an aqueous composition of the said pesticide activeprinciple, or it is added to a pesticide formulate which can be dilutedwith water to obtain the pesticide formulation to be spayed.
 25. Methodfor the treatment of soil, seeds, plants and of any other biologicmaterial which requires the application of pesticides, wherein theimprovement comprises applying thereon the agrochemical compositionaccording to claim 16.